Variable delivery piston pump



Feb. 22, 1966 J. PASKER VARIABLE DELIVERY PISTON PUMP 2 Sheets-Sheet 1 Filed Nov. 9, 1962 Gem/d J Pasker IN VEN TOR.

Feb. 22, 1966 G. J. PASKER 3,236,189

VARIABLE DELIVERY PISTON PUMP Filed Nov. 9, 1962 2 Sheets-Sheet 2 Gerald J Pasker IN VENTOR.

(am Wow Em United States Patent 3,236,189 VARIABLE DELIVERY PISTON PUMP Gerald J. Pasker, Monticello, Iowa; Monticello State Bank and La Von M. Pasker, executors of said Gerald J. Pasker, deceased Filed Nov. 9, 1962, Ser. No. 236,625 3 Claims. (Cl. 103-173) This invention comprises a variable delivery piston pump and more particularly pertains to a pump of the reciprocating piston constant stroke type having improved means for feeding fluid into and discharging fluid under compression from the pumping chambers together with means for controllably varying the effective capacity of the pump while maintaining its constant stroke.

A further object of the invention is to provide a device in accordance with the preceding objects wherein a single adjustable means is provided for effectively controlling the effective delivery or capacity of all of the pump cylinders of the device.

Still another object of the invention is to provide a pump having an improved mechnism for eifecting reciprocation of the pump pistons with a constant stroke in a compact arrangement together with improved means for providing within the pump casing a reservoir for the fluid to be admitted to the pump and bypass means for effecting rejection of a predetermined and adjustable portion of the inducted pump charge to return a portion of the charge of the pump cylinders to the fluid supply chamber.

A still further object of the invention is to provide a pump construction which may have a constant volmetric capacity and wherein a fuel supply chamber houses the connecting means for imparting reciprocation to the pump pistons and also supplies fluid through the pump positions into the working chambers of the pump.

These together with other objects and advantages which will become subsequently apparent inside the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is an elevational view, parts being broken away and shown in section of a preferred embodiment of a variable delivery reciprocating piston pump in accordance with this invention;

FIGURE 2 is a view in end elevation taken from the left side of FIGURE 1 with parts being broken away and shown in vertical transverse section and certain concealed parts being shown in dotted line therein;

FIGURE 3 is a vertical central longitudinal sectional view taken upon an enlarged scale substantially upon the plane indicated by the section line 3-3 of FIGURE 2 and showing the internal construction of the pump, with parts broken away and shown in section and with certain concealed parts and alternative positions of parts being shown in dotted lines;

FIGURE 4 is a vertical transverse sectional view taken upon a reduced scale substantially upon the plane indicated by the section line 4-4 of FIGURE 3 and showing in particular a view of the pump housing taken from the right end thereof and with the end cover plate removed therefrom; and

FIGURE 5 is a view taken upon a reduced scale substantially upon the plane indicated by the broken section line 55 of FIGURE 3 and showing in vertical transverse section certain further details of the internal construction of the pump.

It should be understood that in its preferred form the principles of this invention are embodied in a reciprocating piston pump having a constant stroke but a variable delivery and in which the variable delivery is effected by ice rejecting a predetermined adjustable portion of the chanrge compressed in each pump cylinder and returing this reection charge to the fluid supply chamber of the pump. Other features of the invention, however, are applicable to pumps of the same general construction but wherein the variable delivery and charge rejecting feature is omitted therefrom.

In the accompanying drawings, the numeral 10 designates generally a multiple cylinder pump in accordance with this invention. This pump includes a generally cylindrical pump body or housing 12 having therein a plurality of pump cylinders or chambers 14 disposed in a parallel side-by-side relation and spaced equidistantly from and about a central axis of the body. The cylinders open at one end of the body which open end is closed by an end plate 16 comprising an end wall of the body and which is removably secured thereto as by fastening bolts 18. The other end of the body is provided with an enlarged chamber or compartment 20 in which is housed the conecting mechanism by which the individual pump pistons 22, each reciprocable in one of the cylinders 14, are operatively connected to a drive shaft 23 which is journaled as by bearings 24 in a removable end wall or closure 26 secured as by bolts 28 to the corresponding end of the pump housing 12.

It is to be understood that power from any suitable source is applied to the drive shaft 23 and through the connecting means to be herein after set forth, impacts reciprocation to the pump pistons 22.

The compartment 20 not only serves as a chamber to house the connecting means by which the pump pistons are secured to the drive shaft 23, but also serves as a fiuid supply chamber. Any suitable fluids to be pumped whether a gas or liquid is delivered to the fluid supply chamber as by a supply conduit 30 connected to the tubular boss 32 and which communicates with an inlet port 34 into this chamber.

The open ends of the cylinders 14 are provided with cylinder heads in the form of cylindrical members 36 which have flanges 38 received in recesses 40 in the end plate 16 by which latter member the flanges and thus the cylinder heads are clamped against the endof the associated pump cylinder. Suitable O-ring or other packing means as at 42 may be utilized to establish a fluid tight seal between the cylinder head flanges and the recesses 40 and the end plate 16 as shown in FIGURE 3.

Each cylinder head is likewise provided with a sealing ring such as an O-rig 44 diposed in a peripheral chnnel or groove upon the exterior thereof and engaged against the inside wall of the associated cylinder.

With continuing reference to FIGURE 3 it will be observed that each cylinder head has a tubular axial inwardly extending projection 46 and there is a diametrically enlarged bore or recess as at 48 upon the reverse side of the cylinder head. There is thus provided by this bore a valve seat 50 which is controlled by a non-return outwardly opening check valve 52 which is spring-urged as at 54 to its closed position. The spring 54 in turn may be seated upon an inwardly projecting centering pin 56 carried by the end plate 16.

Each of the bores 48 in the cylinder heads communicates with an annular delivery chamber 60 formed on the inner face of the plate 16, and which chamber communicates with an aligned passage 62 formed in the housing. The opposite ends of the passage 62 are sealed as by O-rings 64 and 66 to corresponding ports in the end plates 16 and 26, the latter end plate having a discharge passage 68 which communicates with a delivery conduit 70 carrying the compressed fluid to any suitable destination.

Each of the pistons 22 comprises a hollow shell having a cylindrical skirt 72 slidab-ly received in the corresponding cylinder 14. This skirt defines a bore or chamber 74 opening from its inward extremity into a compression chamber or Working chamber 76 in the cylinder. The bore 74 communicates with a diametrically reduced bore 78 by means of an annular shoulder 80 upon Which is received a spider or other bridging means 82 against which abuts one end of a compression spring 84 whose other extremity is seated upon and surrounds the tubular projection 46 of the cylinder head as previously mentioned. The spring thus yieldingly urges the piston away from the cylinder head.

At the inward extremity of the diametrically reduced bore 78 there is provided a valve seat 86 with which a ball check valve 88 cooperates, the valve being urged as by a spring 90 to its valve closing position. This spring is seated upon an axially projecting extension 92 of the spider or spring-retaining member 82.

The reduced bore 78 terminates at its inner end in a further diametrically reduced bore 94 which is closed, this bore having a plurality of laterally extending ports 96 establishing communication with the interior of the fluid inlet storage chamber 20. The chamber is thus at all times in communication with the interior of the bore 94 so that fluid may pass by the check valves 88 into the skirt of the piston and thus into the working or compression chamber 76, and after compression therein, may be discharged past the delivery check valve 52 and into the delivery conduit 62.

In order to effect reciprocation of the pistons in their cylinders, a connecting means is provided which operatively connects the inner faces of the pistons with the drive shaft 23. For this purpose, the drive shaft is provided with a wobble-r or swash plate 100 having an annular face 102 which is inclined to the axis of rotation of this plate and of the drive shaft 23. The plate is further provided with a correspondingly inclined inwardly projecting stub shaft 104 upon which is rotatably mounted by a bearing assembly 106 a Wobbler or swash plate 108 which bears against the inclined cam surface 102 as by a bearing assembly 110. The plate 108 in turn abuts against the corresponding extremities of the pistons, which latter are held against the plate by the action of the springs 84.

The arrangement is such that in accordance with a conventional Wobbler or swash plate mechanism, rotation of the shaft 23 through the inclination of the plate 108 will produce a reciprocation of the pistons in their cylinders and thus generate the pumping or working stroke of the pistons.

As will be seen by reference particularly to FIGURES 2-4, the exterior surface of the housing 12 may be provided with a plurality of circumferentially spaced and axially extending fins 120 defining grooves or channels 122 therebetween. These fins facilitate the cooling of the pump by dissipating any heat generated by the compres sion therein.

As so far described the pump is effective for providing a constant stroke and constant delivery of fluid. This fluid is supplied into the chamber 20 which serves as a reservoir to provide a constant supply of fluid for the pumping chambers and alsoserves to cool and if the fluid is of a liquid nature may serve to lubricate the connecting mechanism by which the pump pistons are connected to the drive shaft 23. There is thus provided a uni-flow action or passage of the fluid from the chamber 20, through the pistons, through the pumping chambers and through the outlet ports to the delivery chamber 60 and from thence to the conduit 62 and to the final discharge conduit 70. This produces a very compact device which can be readily serviced by merely removing the corresponding end plates whereby access can be had to the fluid inlet compartment and the connecting mechanism at one end of the device or to the cylinder heads and the discharge valves at the other end thereof. In some instances this construction may be found to be satisfactory and the device may be so employed.

In general, however, it is preferred to provide a means for effecting a controlled variable delivery of the pump cylinders while maintaining their constant stroke. For this purpose, the particular construction shown in the drawings is employed.

This feature of the invention utilizes a fluid rejection mechanism whereby any desired portion of the charge compressed by the pump cylinders may be returned directly to the fluid supply compartment 20 thereby reducing correspondingly the fluid which is discharged from the pump into the delivery line thereof.

For this purpose, there is provided an axial passage or bore disposed centrally of the housing '12 and communicating with the compartment .20. This bore is provided with a plurality of longitudinally spaced radially extending rejection ports 132, one set of each such ports communicating with each of the working cylinders of the pump. .As will be noted from FIGURE 3, the rejection ports of one cylinder are staggered with respect to those of the other cylinders although in other instances they may be aligned therewith if desired. Blind bores aligned with these ports may be drilled in the wall of the housing and closed by plugs :134 to prevent the passage of the drills which make the ports 13-2.

Slidably received in the fluid rejection bore 130 and also extending through a corresponding aligned bore 186 in the end plate 16 is a control valve 138 in the form of a plunge-r. The control valve is provided with a recess 140 in which is received the extremity 142 of a control lever 144 journaled as at 146 upon any suitable support such as that indicated at 148. The arrangement is such that by manipulating the lever or handle 144, the plunger may be adjustably positioned axially of the bore 130 so that it will selectively control one or more of the sets of ports 132 therein.

Obviously, when the piston uncovers all of the ports, the entire volume delivered by the reciprocating pump pistons will be discharged through the series of rejection ports and into the rejection bore 130 and thus bypassed back to the fluid storage compartment or chamber 20. Consequently, there will be no fluid delivered past the delivery valves 52 into the delivery passage 60, 62 of the pump. On the other hand, when the plunger is moved all of the way inward so that it covers and closes all of the ports 132, none of the charge compressed in the pump or working chambers will be bypassed or rejected and sent back to the compartment 20. Consequently, the entire stroke of the pump is effective to compress and deliver fluid. The plunger may however be adjusted to a number of intermediate positions covering one or more of the ports 132. Under this condition, varying proportions of the charge will be rejected inasmuch as the charge continues to be rejected until such time as the outermost port which remains uncovered by the control valve 138 is covered by the skirt of the piston. Thereafter, the remainder of the stroke of the piston is effective to compress a fluid charge and deliver it past the valve 52.

It will thus be observed that in this embodiment a single centrally located control valve is effective to simultaneously control and regulate a variable delivery of the pistons of the pump.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A variable delivery reciprocating pump comprising a hollow elongated housing open at opposite ends and having a compartment therein opening at one end, a plurality of open-ended pump cylinders in said housing disposed in circumferentially spaced side-by-side relation about the central axis of said housing, said compartment comprising a crankcase into which one end of each cylinder communicates, the other end of each cylinder opening at the other end of said housing, closure plates for said housing opposite ends comprising a cylinder head cover and a crankcase cover, a drive shaft journaled entirely in said crankcase cover and extending into said compartment, pistons each reciprocable in one of said cylinders and operatively connected to said drive shaft in said compartment, a cylinder head disposed in and closing said other end of each cylinder and forming therewith a pump chamber, means supplying a fluid into said pump chambers, fluid outlet means receiving fluid under pressure from said pump chambers, fluid rejecting means communicating with each pump chamber and receiving fluid therefrom whereby to control the proportion of the delivery of fluid from said pump chambers to said fluid outlet means, and means associated with said fluid rejection means and regulating the delivery of fluid from said pump chambers to said fluid rejection means and thereby adjustably controlling the delivery of said pump chambers, said fluid supplying means and said fluid rejecting means each communicating with said crankcase, a supply passage extending through each piston and connecting the crankcase with the associated pump chamber.

2. The combination of claim 1 wherein said fluid rejecting means includes a passage in said housing disposed between said cylinders and having one end continuously opening into said fluid supply means and having series of longitudinally spaced ports, each series of ports communicating with one of said pump chambers, a control valve movably mounted in said passage and selectively controlling the ports of said series.

3. A variable delivery reciprocating pump comprising a hollow elongated housing open at opposite ends and having a compartment therein opening at one end, a plurality of open-ended pump cylinders in said housing disposed in circumferentially spaced side-by-side relation about the central axis of said housing, said compartment comprising a crankcase into which one end of each cylinder communicates, the other end of each cylinder opening at the other end of said housing, closure plates for said housing opposite ends comprising a cylinder 'head cover and a crankcase cover, a drive shaft journaled entirely in said crankcase cover and extending into said compartment, pistons each reciprocable in one of said cylinders and operatively connected to said drive shaft in said compartment, a cylinder head disposed in and closing said other end of each cylinder and forming therewith a pump chamber, means supplying afluid into said pump chambers, fluid means receiving fluid under pressure from said pump chambers, fluid rejecting means communicating with each pump chamber and receiving fluid therefrom whereby to control the proportion of the delivery of fluid from said pump chambers to said fluid outlet means, and means associated with said fluid rejection means and regulating the delivery of fluid from said pump chambers to said fluid rejection means and thereby adjustably controlling the delivery of said pump chambers, said fluid rejecting means comprising a bore in said housing disposed between said pump chambers, a series of longitudinally spaced ports connecting each pump chamber with said bore and positioned to be successively overrun and blocked by the associated pump piston, a control valve movably mounted in said bore and adjustably movable to positions selectively blocking flow through said ports into said bore.

References Cited by the Examiner UNITED STATES PATENTS 2,479,876 8/1949 Sherman 230186 2,677,326 5/1954 Schindele 103173 2,706,384 4/1955 Schott 10341 2,722,890 11/1955 Lucien 103173 3,151,561 10/1964 Schlanzky et a1 103173 FOREIGN PATENTS 1,013,521 8/1956 Germany.

511,189 1/1955 Italy.

LAURENCE V. EFNER, Primary Examiner.

JOSEPH H. BRANSON, JR., Examiner. 

1. A VARIABLE DELIVERY RECIPROCATING PUMP COMPRISING A HOLLOW ELONGATED HOUSING OPEN AT OPPOSITE ENDS AND HAVING A COMPARTMENT THEREIN OPENING AT ONE END, A PLURALITY OF OPEN-ENDED PUMP CYLINDERS IN SAID HOUSING DISPOSED IN CIRCUMFERENTIALLY SPACED SIDE-BY-SIDE RELATION ABOUT THE CENTRAL AXIS OF SAID HOUSING, SAID COMPARTMENT COMPRISING A CRANKCASE INTO WHICH ONE END OF EACH CYLINDER COMMUNICATES, THE OTHER END OF EACH CYLINDER OPENING AT THE OTHER END OF SAID HOUSING, CLOSURE PLATES FOR SAID HOUSING OPPOSITE ENDS COMPRISING A CYLINDER HED COVER AND A CRANKCASE COVER, A DRIVE SHAFT JOURNALED ENTIRELY IN SAID CRANKCASE COVER AND EXTENDING INTO SAID COMPARTMENT, PISTONS EACH RECIPROCABLE IN ONE OF SAID CYLINDERS AND OPERATIVELY CONNECTED TO SAID DRIVE SHAFT IN SAID COMPARTMENT, A CYLINDER HEAD DISPOSED IN AND CLOSING SAID OTHER END OF EACH CYLINDER AND FORMING THEREWITH A PUMP CHAMBER, MEANS SUPPLYING A FLUID INTO SAID PUMP CHAMBERS, FLUID OUTLET MEANS RECEIVING FLUID UNDER PRESSURE FROM SAID PUMP CHAMBERS, FLUID REJECTING MEANS COMMUNICATING WITH EACH PUMP CHAMBER AND RECEIVING FLUID THEREFROM WHEREBY TO CONTROL THE PROPORTION OF THE DELIVERY OF FLUID FROM SAID PUMP CHAMBERS TO SAID FLUID OUTLET MEANS, AND MEANS ASSOCIATED WITH SAID FLUID REJECTION MEANS AND REGULATING THE DELIVERY OF FLUID FROM SAID PUMP CHAMBERS TO SAID FLUID REJECTION MEANS AND THEREBY ADJUSTABLY CONTROLLING THE DELIVERY OF SAID PUMP CHAMBERS, SAID FLUID SUPPLYING MEANS AND SAID FLUID REJECTING MEANS EACH COMMUNICATING WITH SAID CRANKCASE, A SUPPLY PASSAGE EXTENDING THROUGH EACH PISTON AND CONNECTING THE CRANKCASE WITH THE ASSOCIATED PUMP CHAMBER. 